Baryogenesis in a supersymmetric model with Z3 matter parity.

Abstract

We analyze a scenario for baryogenesis at low temperature ([similar to]1 TeV) in supersymmetric extensions of the standard model. These extensions contain gauge singlets and discrete symmetries that suppress unwanted baryon- and lepton-number violation, and offer a framework to accommodate nonstandard neutrino physics. In our scenario, the decay of the lightest supersymmetric particle generates a net lepton number that is subsequently converted, via anomalous electroweak processes, into baryon number. We find that this possibility could be realized in models incorporating a [ital Z][sub 3] discrete symmetry, although it requires a scalar singlet as the lightest supersymmetric particle and a somewhat complicated pattern of couplings and fields in the singlet sector.